.header-box {
    width: 100%;
    height: 50px;
    border-bottom: 1px solid #ccc;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-left {
    width: 50%;
}

.header-right {
    flex: 1
}